JPH0513761U - Printer - Google Patents

Abstract

(57) [Abstract] [Purpose] When changing the print color, the ink ribbon may get caught due to insufficient gap between the print head and card holder.
Prevents the occurrence of switching failures and color mixing failures. [Arrangement] An interval changing mechanism K is provided which can change the interval between the print head 5 and the card holder 1. This interval variable mechanism K
Supports the card holder 1 on the carriage 3 so that the card holder 1 can swing around a fulcrum 4, allows it to approach and separate from the platen 7, and biases the card holder 1 in the direction of separation by a spring 9.
A cam 2 for swinging the card holder 1 in the proximity direction against the biasing force is provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a printer, and more particularly, to a printer having an improved paper holding mechanism of a dot impact printer.

[0002]

[Prior Art]

 Conventionally, for example, a dot impact printer includes a paper retainer (hereinafter referred to as a “card holder”) that presses the paper on the platen, and a print head that prints with an ink ribbon against the platen, and uses an ink ribbon as the card holder. It is designed to be inserted between the print head and the print head.

The card holder is fixed to the carriage during production. Therefore, the physical positional relationship between the print head and the card holder, which are fixed on the same carriage, is constant and cannot be easily changed.

[0004]

[Problems to be solved by the device]

 By the way, in this conventional printer, the distance between the print head and the surface of the paper at the time of impact is determined by the performance of the print head. As a result, the distance between the print head and the card holder has been determined to be optimal at impact. Therefore, it is not possible to easily change to another optimum interval when changing the print color. That is, if the distance between the print head and the card holder is narrow, the ink ribbon may get caught in the print head or the card holder, and when switching the print color that moves the ink ribbon, switching failure, ribbon stains, and color mixing However, there is a problem that it may cause problems.

The present invention has been made in view of the above problems, and an object thereof is to provide a printer in which an ink ribbon can be easily moved.

[0006]

[Means for Solving the Problems]

 To achieve the above object, the printer of the present invention comprises a paper presser for pressing the paper on the platen and a print head facing the platen for printing with an ink ribbon, and the ink ribbon is provided between the paper presser and the print head. The printer is designed to be inserted, and is provided with a variable spacing mechanism that changes the distance between the paper retainer and the print head.

Then, if necessary, the interval varying mechanism section is provided with the paper presser capable of approaching and separating from the platen, and a spring for biasing the paper presser in one of the approaching and separating directions. A cam is provided to drive the paper retainer against the biasing force of the spring.

[0008] Furthermore, a structure is provided that includes a mechanism portion that separately changes the distance between the platen and the paper pressing member, the distance between the print head and the platen.

[0009]

[Action]

 According to the printer configured as described above, the interval between the paper retainer and the print head is widened when switching the print colors. This makes it easier for the ink ribbon to move within the space and prevents the ink ribbon from being caught.

[0010]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing a printer according to an embodiment of the present invention.

In the figure, reference numeral 1 denotes a card holder as a paper pressing member for pressing a paper 11 on the platen 7. Reference numeral 1a is a guide sheet fixed to the card holder 1. Reference numeral 5 is a print head supported by the carriage 3, and 6 is an ink ribbon inserted between the card holder 1 and the print head 5. The card holder 1 is formed in an L-shaped cross section, and is supported by the carriage 3 with its corner portion serving as a fulcrum 4.

K is a variable spacing mechanism that allows the card holder 1 to move toward and away from the platen 7 by means of the fulcrum 4, and a spring 9 that biases the card holder 1 in the direction away from the platen 7. Is equipped with. The spring 9 is held by a fixing screw 8 screwed into the carriage 3.

Reference numeral 2 denotes a cam for rocking the card holder 1 against the biasing force of the spring 9. This cam 2 is mounted on the carriage 3 in a rotatable state by an electromagnetic solenoid (not shown) or the like, and the distance from the contact surface with the card holder 1 to the center of rotation is one of a plurality of cam surfaces. The structure is selectable. The height of the cam surface increases as it rotates counterclockwise in the figure. The spring 9 presses the card holder 1 against the cam 2.

Further, in addition to the distance varying mechanism K, a mechanism portion described later for varying the distance between the print head 5 and the platen 7 is provided.

Therefore, according to this printer, the printing paper 11 is inserted so as to be wound around the platen 7, and is printed by the print head 5 via the ink ribbon 6 while being guided by the card holder 1. The intervals between the print head 5, the print platen 7, and the card holder 1 are determined so as to be optimal at the time of impact.

The gap from the print head 5 to the platen 7 is determined by the absolute thickness of the paper 11, the thickness of the ink ribbon 6, and the ideal GAP at the time of impact due to the characteristics of the print head 5. (Not shown) by using the eccentricity provided on the guide shaft 10.

Further, in general, when performing color printing, the print color is switched by swinging the position of the ink ribbon 6 up and down. At that time, however, an instruction for color switching is issued from the host device. By driving an electromagnetic solenoid (not shown) so as to rotate the cam 2 counterclockwise when it is sent, the contact cam surface with the card holder 1 is changed to a higher level, and the card holder 1 is moved. The fulcrum 4 is rotated clockwise to widen the distance between the print head 5 and the card holder 1. As a result, the ink ribbon 6 is moved without being scratched.

After the color change is completed, the card holder 1 is rotated counterclockwise by rotating the cam 2 in the clockwise direction, and the distance between the card holder 1 and the print head 5 is changed to the regular position.

As a means for changing the distance between the card holder 1 and the print head 5, the method of changing the contact state between the cam 2 and the card holder 1 has been described, but if it is a method of changing the contact height, A method of sliding laterally may be used, and the same effect can be obtained. Further, in the present description, the electromagnetic solenoid has been described as the method for rotating the cam 2, but it goes without saying that a motor may be used, for example.

[0020]

[Effect of the device]

 As described above, according to the printer of the present invention, the distance between the platen and the card holder can be adjusted, so that the distance between the print head and the card holder can be widened when changing the printing color. Since the ink ribbon can be easily moved, it is possible to prevent defects such as switching defects and ribbon stains.

[Brief description of drawings]

FIG. 1 is a diagram showing a printer according to an embodiment of the present invention.

[Explanation of symbols]

 K spacing variable mechanism 1 Card holder (paper presser) 1a Guide sheet 2 Cam 3 Carriage 4 Support point 5 Print head 6 Ink ribbon 7 Platen 8 Fixing screw 9 Spring 10 Guide shaft 11 Paper

Claims (3)

[Scope of utility model registration request] 1. A paper retainer for retaining the paper on the platen,
In a printer that includes a print head that faces the platen and prints with an ink ribbon, and the ink ribbon is inserted between the paper retainer and the print head, a variable spacing mechanism section that changes the distance between the paper retainer and the print head. A printer comprising: 2. The distance varying mechanism portion is provided with the paper presser capable of approaching and separating from the platen, and provided with a spring for urging the paper presser in one of the approaching and separating directions. 2. The printer according to claim 1, further comprising a cam for driving the paper pressing member against the biasing force. 3. The printer according to claim 1, further comprising a mechanism section that separately changes the distance between the platen and the paper retainer and the distance between the print head and the platen.